Merge branch 'linux-linaro-lsk-v4.4' into linux-linaro-lsk-v4.4-android

[firefly-linux-kernel-4.4.55.git] / arch / arm64 / include / asm / efi.h

diff --git a/arch/arm64/include/asm/efi.h b/arch/arm64/include/asm/efi.h
index 8e88a696c9cbcbd2c8f717ea1c929b87750f1b03..932f5a56d1a60d47ffc7b8c05ce2e67ea7374e7a 100644 (file)
--- a/arch/arm64/include/asm/efi.h
+++ b/arch/arm64/include/asm/efi.h
@@ -1,6 +1,7 @@
 #ifndef _ASM_EFI_H
 #define _ASM_EFI_H
 
+#include <asm/cpufeature.h>
 #include <asm/io.h>
 #include <asm/mmu_context.h>
 #include <asm/neon.h>
@@ -69,7 +70,30 @@ int efi_create_mapping(struct mm_struct *mm, efi_memory_desc_t *md);
 
 static inline void efi_set_pgd(struct mm_struct *mm)
 {
-       switch_mm(NULL, mm, NULL);
+       __switch_mm(mm);
+
+       if (system_uses_ttbr0_pan()) {
+               if (mm != current->active_mm) {
+                       /*
+                        * Update the current thread's saved ttbr0 since it is
+                        * restored as part of a return from exception. Set
+                        * the hardware TTBR0_EL1 using cpu_switch_mm()
+                        * directly to enable potential errata workarounds.
+                        */
+                       update_saved_ttbr0(current, mm);
+                       cpu_switch_mm(mm->pgd, mm);
+               } else {
+                       /*
+                        * Defer the switch to the current thread's TTBR0_EL1
+                        * until uaccess_enable(). Restore the current
+                        * thread's saved ttbr0 corresponding to its active_mm
+                        * (if different from init_mm).
+                        */
+                       cpu_set_reserved_ttbr0();
+                       if (current->active_mm != &init_mm)
+                               update_saved_ttbr0(current, current->active_mm);
+               }
+       }
 }
 
 void efi_virtmap_load(void);